And we already have the decimal cut off, it’s 3.14. You can even find a dozen scientific papers as to why this is specific enough for almost every purpose.
But that's exactly a little lie, in contrast to reality. The truth is, Pi is an irrational number. This means every decimal representation is necessarily wrong, or a "lie", if you insist. Wether someone deems it accurate "enough" for "almost every purpose" is their opinion. It's still not the number Pi. If you want to write Pi down in decimal representation, you need to use infinitely many digits. If you use less, you did not write down Pi. Anyone suggesting something else is feeding you a little lie.
The intent of this paragraph was not to encourage you to always fully spell out Pi, but to lead the idea ad absurdum. It should be apparent that there are situations when it is practical, even necessary, to simplify reality to something we can handle.
Science education is full of these situations.
For example, when learning about the composition of atoms, you might first hear about them in the context of Chemistry. And use the Nuclear shell model, which imagines electrons to exist in tidy, circular orbits around the nucleus. Later your teacher might hint at another representation, Atomic orbitals. Later still you might learn about quantum mechanics and describe everything in Wave functions.
Which is reality? While they live in a spectrum from 'easier to understand' to 'more accurate'; Neither! They all are models. They all are human creations. Made by humans, for humans, to talk about reality. They are tools of communication tailored to specific use cases and audiences. Because reality is infinitely complex, but our understanding is always limited.
If you think about it, you will find endless examples like these in your journey how you learned science. We are unable to experience reality as it is, and need to wrap it in language and models. We are also curious at very young ages, and need models and language which is appropriate to our still developing individual capability. We need to embrace these little lies to stand on shoulders of giants.
It has some irony that someone is arguing for an inaccurate value of Pi in a meme post which is all about Pi being used inaccurately, while complaining about "little lies".
If you want to talk about this opinion piece: Rayman himself says they are using many more digits, because two digits is not enough. Pi is also used in many more fields than astronomy. So to assume "all we ever need is two digits of Pi" because astronomers consider that to be enough "for most calculations" seems a bit short-sighted.
For example, if you repeatedly multiply a value by something with Pi, over many million iterations, you absolutely want more accuracy. The example given in the article is very specific. It's a nice insight, but no basis for generalization.
In the end, if you insist this simplification is sufficient, you're making the very point I was making: Sometimes, we don't need the full complexity of reality, but "a little lie" is fully sufficient and much easier to understand and deal with. However, students should understand that's not the full story, probably never will be.